This invention relates generally to clutches and, more particularly, to clutch assemblies for trucks adapted for use with flat flywheels (as opposed to flywheels with peripheral rims).
Clutch assemblies of the type shown in U.S. Pat. No. 3,394,788 are designed for use with rimmed flywheels and comprise a heavy-duty cast metal clutch cover which is adapted to be secured (e.g., bolted) directly to the rim of the flywheel. The cover has a relatively narrow or thin profile (i.e., the axial dimension of the cover is substantially less than the overall axial dimension of the clutch), the axial dimension of the rim of the flywheel being sufficient to accommodate the friction disk assembly and pressure plate assembly generally within the rim. This type of clutch has proven to be relatively durable. Clutches designed for use with rimless (i.e., flat) flywheels have also been developed. This latter type of clutch comprises a lightweight clutch cover of stamped metal which is adapted to be secured at its periphery directly to the flat face of the flywheel. The cover has a relatively wide profile (that is, its axial dimension is relatively large) to accommodate the inner workings of the clutch, including the friction disk and pressure plate assemblies. Unlike the cast metal thin-profile cover clutch, this latter clutch design has not been a substantially durable one, due in significant part to the deficiencies in the relatively lightweight stamped-metal clutch cover.
Accordingly, there is a need in the clutch industry (especially in the clutch rebuilding industry) to replace the wide-profile cover with the prior heavy-duty thin-profile cover with modifications enabling use of the heavy-duty cover with flat rimless flywheels.